Dave -- is this an accurate synopsis of the problem?
- wiper motion never stops prior to three complete cycles after the switch lever/stalk is released when the wash mode is selected
- occasionally, wiper motion stops when the switch is set to either slow or fast continious wiping
- frequently, wiper motion stops when the switch is set to intermittant wiping
- when stops occur, the blades are parked in the normal position at the bottom edge of the windshield
- stops generally last about ten minutes and motion is resumed without any manipulation of the switch stalk.

Please correct any of my mistakes in this synopsis and add anything else that you can think of - if necessary, after your next drive in the rain.
I'll be out of town until the end of the month but in the meantime, it would be helpful if another member could chime in about where the timing function of the wipers is located. I can find nothing in any of my materials. Is it located in the combination switch on the steering column; at the wiper motor; or, in some control module? Surely, wiper control is not done with digital signal!

Geoff